1. Field of the Invention
The present invention relates to an extension structure for a tool such as a wrench or the like, and more particularly to an extension structure which can be assembled easily and quickly and has a rigid construction.
2. Description of the Related Art
The closest prior art reference of which the applicant is aware is disclosed in the Taiwanese Patent Publication No. 88221334, entitled by “Main body of Wrench Extension”, which disclosed a wrench extension including a main body, a push ring, and relative push and locking mechanisms. However, the structure of the wrench extension is complicated, and cannot be assembled easily, thereby causing inconvenience in assembly, and thereby increasing cost of fabrication.
Another prior art references are disclosed in the U.S. Pat. No. 6,199,457-B1, the U.S. Pat. No. 6,267,032-B1, and the U.S. Pat. No. 6,523,441-B2.